using nuclear energy tend to favour disposal of Low-Level and
Intermediate-Level radioactive waste in mined repositories consisting of series
of tunnels or drifts connected to disposal tunnels at a few hundred meters
depth. Abandoned mines can serve as repositories for such waste and the present
study indicates that this would be possible also for High-Level Waste in the
form of spent reactor fuel. The technique implies encapsulation of such waste
in metal canisters surrounded by densely compacted smectite clay in relatively shallow
mined repositories as well as in very deep bored holes. Intermediate-Level radioactive
waste can be disposed of in caverns in the form of packages of metal containers
cast in low-pH concrete and embedded in dense smectitic clay.
Keywords: Low-Level and Intermediate-Level radioactive waste (LLW and ILW), smectite clay, compaction,
excavation disturbed zone (EDZ), crystalline rock, numerical modelling.